you really only see this in dating sims but the tokimemo girl's side falls into this easily, 1&2 focuses on the jealousy between mc and the female rivals, but 3&4 is the jealousy between the LIs. for non-otome, there's the rune factory games but more specifically 4&5, the jealousy mechanics aren't very deep and is just an extra piece of dialogue though
for VNs, i can really only think of ozmafia? it has a dating mechanic for these 3 characters where you can basically switch over to another LI in that group if you spend more time with him compared to the original LI you picked. i don't really remember much about ozmafia so i'm kinda unsure how much jealousy plays into this